Offline validator for an Austrian Firmenbuchnummer (FN), the company register number
Offline validator for an Austrian Firmenbuchnummer (FN), the company register number. Normalizes the numeric part (1-6 digits, left-padded to 6 for calculation), computes the modulo-11 check letter using weights 2,1,2,1,2,1 (Luhn-style digit reduction for products >=9 by subtracting 9) and the standard letter table (0=p,1=a,2=b,3=c,4=d,5=e,6=f,7=g,8=h,9=i,10=k), and compares it to the supplied check letter.
1000 (raw units)
price
1
calls / 30d
1
unique payers
2026-09-09
updated
Provider
toll402.dev · discovered, not yet claimed by its owner
Payment (x402 accepts[])
[
{
"scheme": "exact",
"network": "eip155:8453",
"payTo": "0x318d34fa0bd69eff17fac648d2df8cf7a88b3dbe",
"asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
"amount": "1000",
"maxTimeoutSeconds": 300
}
]Output schema
{
"bazaar": {
"info": {
"input": {
"body": {
"value": "123456k"
},
"bodyType": "json",
"method": "POST",
"type": "http"
},
"output": {
"example": {
"ok": true
},
"type": "json"
}
},
"schema": {
"$schema": "https://json-schema.org/draft/2020-12/schema",
"properties": {
"input": {
"additionalProperties": false,
"properties": {
"body": {
"additionalProperties": false,
"properties": {
"value": {
"description": "Firmenbuchnummer, e.g. 'FN 123456k' or '123456k'",
"type": "string"
}
},
"required": [
"value"
],
"type": "object"
},
"bodyType": {
"enum": [
"json",
"form-data",
"text"
],
"type": "string"
},
"method": {
"enum": [
"POST"
],
"type": "string"
},
"type": {
"const": "http",
"type": "string"
}
},
"required": [
"type",
"method",
"bodyType",
"body"
],
"type": "object"
},
"output": {
"properties": {
"example": {
"type": "object"
},
"type": {
"type": "string"
}
},
"required": [
"type"
],
"type": "object"
}
},
"required": [
"input"
],
"type": "object"
}
}
}Use it
curl
curl "https://toll402.dev/v1/t/fn_at_validate" # -> 402 Payment Required, accepts[] lists how to pay # retry with a PAYMENT-SIGNATURE (or PAYMENT header) once paid
JavaScript
const res = await fetch("https://toll402.dev/v1/t/fn_at_validate");
if (res.status === 402) {
const { accepts } = await res.json();
// pay one of accepts[] via an x402 client, then retry with the payment header
}Python
import httpx
res = httpx.get("https://toll402.dev/v1/t/fn_at_validate")
if res.status_code == 402:
accepts = res.json()["accepts"]
# pay one of accepts[] via an x402 client, then retry with the payment headerMachine-readable
Everything on this page is also available as clean JSON at /resources/7039.json, and this resource appears in /discovery/resources and /discovery/search.